The palynostratigraphy of two sediment cores
from Soppensee, Central Switzerland (596 m asl) was
correlated with nine regional pollen assemblage zones
defined for the Swiss Plateau. This biostratigraphy
shows that the sedimentary record of Soppensee includes
the last 15 000 years, i.e. the entire Late-glacial and
Holocene environmental history. The vegetation history
of the Soppensee catchment was ... read more inferred by pollen and
plant-macrofossil analyses on three different cores taken
in the deepest part of the lake basin (27 m). On the basis
of a high-resolution varve and calibrated radiocarbon
chronology it was possible to estimate pollen accumulation
rates, which together with the pollen percentage
data, formed the basis for the interpretation of the past
vegetation dynamics. The basal sediment dates back to
the last glacial. After reforestation with juniper and
birch at ca. 12 700 B.P., the vegetation changed at
around 12 000 B.P. to a pine-birch woodland and at the
onset of the Holocene to a mixed deciduous forest. At ca.
7000 B.P., fir expanded and dominated the vegetation
with beech becoming predominant at ca. 500 ¹⁴C-years
later until sometime during the Iron Age. Large-scale
deforestation, especially during the Middle Ages, altered
the vegetation cover drastically. During the Late-glacial
period two distinct regressive phases in vegetation development
are demonstrated, namely, the Aegelsee oscillation
(equivalent to the Older Dryas biozone) and the
Younger Dryas biozone. No unambiguous evidence for
Holocene climatic change was detected at Soppensee.
Human presence is indicated by early cereal pollen and
distinct pulses of forest clearance as a result of human
activity can be observed from the Neolithic period onwards. show less